Media content distribution systems are becoming more and more popular. The data throughput of the associated distribution platforms such as YouTube and iTunes is immense. As a result, increasingly sophisticated data compression techniques are developed.
Data compression techniques are generally based on so-called codecs. The Advanced Video Coding (AVC) standard, also known as H.264 or Moving Pictures Expert Group (MPEG)-4 Part 10, defines a video compression codec that is based on eliminating redundancies both between subsequent pictures (temporal redundancy) as well as within a single picture (spatial redundancy) of a picture stream.
Scalable Video Coding (SVC) as specified in Annex G of the H.264/AVC specification allows the construction of a video bitstream that contains scaling sub-bitstreams each conforming to H.264/AVC. An encoded video bitstream is called scalable when parts of the bitstream can be removed such that the resulting sub-bitstream can still be decoded by a target decoder. The video content of the sub-bitstream can be reconstructed at a quality that is less than that of the original bitstream, but still high when considering the resulting reduction of transmission and storage resources
AVC and SVC codecs are generally regarded as single-view video codecs, which means that redundancies are eliminated within the picture stream generated by a single video camera. Upcoming video features such as 3D (“stereoscopic”) video and free viewpoint video are based on multiple picture streams generated by multiple video cameras.
Multi View Coding (MVC) as specified in Annex H of the H.264/AVC specification defines a video codec for multi-view scenarios. To increase the compression efficiency, MVC additionally exploits redundancies between pictures streams generated by different video cameras directed to essentially the same scene (but, e.g., from different positions).
Existing multi-view video codecs have to a large extent been built upon their single-view counterparts. With respect to MVC, reference is made to Peter Merkle, Karsten Müller, Aljoscha Smolic, and Thomas Wiegand: Efficient Compression of Multi-View Video Exploiting Inter-View Dependencies Based on H.264/MPEG4-AVC, IEEE International Conference on Multimedia and Expo (ICME'06), Toronto, Ontario, Canada, July 2006 and Michael Dröse, Carsten Clemens, and Thomas Sikora: Extending Single-View Scalable Video Coding to Multi-View based on H.264/AVC, IEEE International Conference on Image Processing (ICIP'06), Atlanta, Ga., USA, October 2006.
After a single-view video codec has been standardized, it typically takes months or even years until the associated multi-view codec becomes available. As an example, standardization of AVC was completed in 2003 and its SVC extension was standardized in 2007, but the MVC standard was introduced only in 2009. By the time a multiview codec derived from an existing single-view video codec has been standardized, there may thus already be a new single-view codec available with significantly improved compression efficiency.
At present, a new single-view video standard called High Efficiency Video Coding (HEVC), a successor to AVC, is being developed. As it may take years to standardize the multi-view counterpart of HEVC, it would be desirable to immediately make use of HEVC codecs for multi-view purposes instead of relying on existing multi-view video codecs such as MVC.